Hard Problem of Consciousness

We have touched on this in various places, and in particular in this discussion of zombies, but we are now in a position to give a more precise answer.

Bill Vallicella has a discussion of Thomas Nagel on this issue:

Nagel replies in the pages of NYRB (8 June 2017; HT: Dave Lull) to one Roy Black, a professor of bioengineering:

The mind-body problem that exercises both Daniel Dennett and me is a problem about what experience is, not how it is caused. The difficulty is that conscious experience has an essentially subjective character—what it is like for its subject, from the inside—that purely physical processes do not share. Physical concepts describe the world as it is in itself, and not for any conscious subject. That includes dark energy, the strong force, and the development of an organism from the egg, to cite Black’s examples. But if subjective experience is not an illusion, the real world includes more than can be described in this way.

I agree with Black that “we need to determine what ‘thing,’ what activity of neurons beyond activating other neurons, was amplified to the point that consciousness arose.” But I believe this will require that we attribute to neurons, and perhaps to still more basic physical things and processes, some properties that in the right combination are capable of constituting subjects of experience like ourselves, to whom sunsets and chocolate and violins look and taste and sound as they do. These, if they are ever discovered, will not be physical properties, because physical properties, however sophisticated and complex, characterize only the order of the world extended in space and time, not how things appear from any particular point of view.

The problem might be condensed into an aporetic triad:

1) Conscious experience is not an illusion.

2) Conscious experience has an essentially subjective character that purely physical processes do not share.

3) The only acceptable explanation of conscious experience is in terms of physical properties alone.

Take a little time to savor this problem. Note first that the three propositions are collectively inconsistent: they cannot all be true.  Any two limbs entail the negation of the remaining one. Note second that each limb exerts a strong pull on our acceptance.  But we cannot accept them all because they are logically incompatible.

Which proposition should we reject? Dennett, I take it, would reject (1). But that’s a lunatic solution as Professor Black seems to appreciate, though he puts the point more politely. When I call Dennett a sophist, as I have on several occasions, I am not abusing him; I am underscoring what is obvious, namely, that the smell of cooked onions, for example, is a genuine datum of experience, and that such phenomenological data trump scientistic theories.

Sophistry aside, we either reject (2) or we reject (3).  Nagel and I accept (1) and (2) and reject (3). Black, and others of the scientistic stripe, accept (1) and (3) and reject (2).

In order to see the answer to this, we can construct a Parmenidean parallel to Vallicella’s aporetic triad:

1) Distinction is not an illusion.

2) Being has an essentially objective character of actually being that distinction does not share (considering that distinction consists in the fact of not being something.)

3) The only acceptable explanation of distinction is in terms of being alone (since there is nothing but being to explain things with.)

Parmenides rejects (1) here. What approach would Vallicella take? If he wishes to take a similarly analogous approach, he should accept (1) and (2), and deny (3). And this would be a pretty commonsense approach, and perhaps the one that most people implicitly adopt if they ever think about the problem.

At the same time, it is easy to see that (3) is approximately just as obviously true as (1); and it is for this reason that Parmenides sees rejecting (1) and accepting (2) and (3) as reasonable.

The correct answer, of course, is that the three are not inconsistent despite appearances. In fact, we have effectively answered this in recent posts. Distinction is not an illusion, but a way that we understand things, as such. And being a way of understanding, it is not (as such) a way of being mistaken, and thus it is not an illusion, and thus the first point is correct. Again, being a way of understanding, it is not a way of being as such, and thus the second point is correct. And yet distinction can be explained by being, since there is something (namely relationship) which explains why it is reasonable to think in terms of distinctions.

Vallicella’s triad mentions “purely physical processes” and “physical properties,” but the idea of “physical” here is a distraction, and is not really relevant to the problem. Consider the following from another post by Vallicella:

If I understand Galen Strawson’s view, it is the first.  Conscious experience is fully real but wholly material in nature despite the fact that on current physics we cannot account for its reality: we cannot understand how it is possible for qualia and thoughts to be wholly material.   Here is a characteristic passage from Strawson:

Serious materialists have to be outright realists about the experiential. So they are obliged to hold that experiential phenomena just are physical phenomena, although current physics cannot account for them.  As an acting materialist, I accept this, and assume that experiential phenomena are “based in” or “realized in” the brain (to stick to the human case).  But this assumption does not solve any problems for materialists.  Instead it obliges them to admit ignorance of the nature of the physical, to admit that they don’t have a fully adequate idea of what the physical is, and hence of what the brain is.  (“The Experiential and the Non-Experiential” in Warner and Szubka, p. 77)

Strawson and I agree on two important points.  One is that what he calls experiential phenomena are as real as anything and cannot be eliminated or reduced to anything non-experiential. Dennett denied! The other is that there is no accounting for experiential items in terms of current physics.

I disagree on whether his mysterian solution is a genuine solution to the problem. What he is saying is that, given the obvious reality of conscious states, and given the truth of naturalism, experiential phenomena must be material in nature, and that this is so whether or not we are able to understand how it could be so.  At present we cannot understand how it could be so. It is at present a mystery. But the mystery will dissipate when we have a better understanding of matter.

This strikes me as bluster.

An experiential item such as a twinge of pain or a rush of elation is essentially subjective; it is something whose appearing just is its reality.  For qualia, esse = percipi.  If I am told that someday items like this will be exhaustively understood from a third-person point of view as objects of physics, I have no idea what this means.  The notion strikes me as absurd.  We are being told in effect that what is essentially subjective will one day be exhaustively understood as both essentially subjective and wholly objective.  And that makes no sense. If you tell me that understanding in physics need not be objectifying understanding, I don’t know what that means either.

Here Vallicella uses the word “material,” which is presumably equivalent to “physical” in the above discussion. But it is easy to see here that being material is not the problem: being objective is the problem. Material things are objective, and Vallicella sees an irreducible opposition between being objective and being subjective. In a similar way, we can reformulate Vallicella’s original triad so that it does not refer to being physical:

1) Conscious experience is not an illusion.

2) Conscious experience has an essentially subjective character that purely objective processes do not share.

3) The only acceptable explanation of conscious experience is in terms of objective properties alone.

It is easy to see that this formulation is the real source of the problem. And while Vallicella would probably deny (3) even in this formulation, it is easy to see why people would want to accept (3). “Real things are objective,” they will say. If you want to explain anything, you should explain it using real things, and therefore objective things.

The parallel with the Parmenidean problem is evident. We would want to explain distinction in terms of being, since there isn’t anything else, and yet this seems impossible, so one (e.g. Parmenides) is tempted to deny the existence of distinction. In the same way, we would want to explain subjective experience in terms of objective facts, since there isn’t anything else, and yet this seems impossible, so one (e.g. Dennett) is tempted to deny the existence of subjective experience.

Just as the problem is parallel, the correct solution will be almost entirely parallel to the solution to the problem of Parmenides.

1) Conscious experience is not an illusion. It is a way of perceiving the world, not a way of not perceiving the world, and definitely not a way of not perceiving at all.

2) Consciousness is subjective, that is, it is a way that an individual perceives the world, not a way that things are as such, and thus not an “objective fact” in the sense that “the way things are” is objective.

3) The “way things are”, namely the objective facts, are sufficient to explain why individuals perceive the world. Consider again this post, responding to a post by Robin Hanson. We could reformulate his criticism to express instead Parmenides’s criticism of common sense (changed parts in italics):

People often state things like this:

I am sure that there is not just being, because I’m aware that some things are not other things. I know that being just isn’t non-being. So even though there is being, there must be something more than that to reality. So there’s a deep mystery: what is this extra stuff, where does it arise, how does it change, and so on. We humans care about distinctions, not just being; we want to know what out there is distinct from which other things.

But consider a key question: Does this other distinction stuff interact with the parts of our world that actually exist strongly and reliably enough to usually be the actual cause of humans making statements of distinction like this?

If yes, this is a remarkably strong interaction, making it quite surprising that philosophers, possibly excepting Duns Scotus, have missed it so far. So surprising in fact as to be frankly unbelievable. If this type of interaction were remotely as simple as all the interactions we know, then it should be quite understandable with existing philosophy. Any interaction not so understandable would have be vastly more difficult to understand than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will understand such an interaction.

But if no, if this interaction isn’t strong enough to explain human claims of distinction, then we have a remarkable coincidence to explain. Somehow this extra distinction stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that distinction stuff exists isn’t causing people to claim it exists, nor vice versa. Instead humans have some sort of weird psychological quirk that causes them to make such statements, and they would make such claims even if distinction stuff didn’t exist. But if we have a good alternate explanation for why people tend to make such statements, what need do we have of the hypothesis that distinction stuff actually exists? Such a coincidence seems too remarkable to be believed.

“Distinction stuff”, of course, does not exist, and neither does “feeling stuff.” But some things are distinct from others. Saying this is a way of understanding the world, and it is a reasonable way to understand the world because things exist relative to one another. And just as one thing is distinct from another, people have experiences. Those experiences are ways of knowing the world (broadly understood.) And just as reality is sufficient to explain distinction, so reality is sufficient to explain the fact that people have experiences.

How exactly does this answer the objection about interaction? In the case of distinction, the fact that “one thing is not another” is never the direct cause of anything, not even of the fact that “someone believes that one thing is not another.” So there would seem to be a “remarkable coincidence” here, or we would have to say that since the fact seems unrelated to the opinion, there is no reason to believe people are right when they make distinctions.

The answer in the case of distinction is that one thing is related to another, and this fact is the cause of someone believing that one thing is not another. There is no coincidence, and no reason to believe that people are mistaken when they make distinctions, despite the fact that distinction as such causes nothing.

In a similar way, “a human being is what it is,” and “a human being does what it does” (taken in an objective sense), cause human beings to say and believe that they have subjective experience (taking saying and believing to refer to objective facts.) But this is precisely where the zombie question arises: they say and believe that they have subjective experience, when we interpret say and believe in the objective sense. But do they actually say and believe anything, considering saying and believing as including the subjective factor? Namely, when a non-zombie says something, it subjectively understands the meaning of what it is saying, and when it consciously believes something, it has a subjective experience of doing that, but these things would not apply to a zombie.

But notice that we can raise a similar question about zombie distinctions. When someone says and believes that one thing is not another, objective reality is similarly the cause of them making the distinction. But is the one thing actually not the other? But there is no question at all here except of whether the person’s statement is true or false. And indeed, someone can say, e.g, “The person who came yesterday is not the person who came today,” and this can sometimes be false. In a similar way, asking whether an apparent person is a zombie or not is just asking whether their claim is true or false when they say they have a subjective experience. The difference is that if the (objective) claim is false, then there is no claim at all in the subjective sense of “subjectively claiming something.” It is a contradiction to subjectively make the false claim that you are subjectively claiming something, and thus, this cannot happen.

Someone may insist: you yourself, when you subjectively claim something, cannot be mistaken for the above reason. But you have no way to know whether someone else who apparently is making that claim, is actually making the claim subjectively or not. This is the reason there is a hard problem.

How do we investigate the case of distinction? If we want to determine whether the person who came yesterday is not the person who came today, we do that by looking at reality, despite the fact that distinction as such is not a part of reality as such. If the person who came yesterday is now, today, a mile away from the person who came today, this gives us plenty of reason to say that the one person is not the other. There is nothing strange, however, in the fact that there is no infallible method to prove conclusively, once and for all, that one thing is definitely not another thing. There is not therefore some special “hard problem of distinction.” This is just a result of the fact that our knowledge in general is not infallible.

In a similar way, if we want to investigate whether something has subjective experience or not, we can do that only by looking at reality: what is this thing, and what does it do? Then suppose it makes an apparent claim that it has subjective experience. Obviously, for the above reasons, this cannot be a subjective claim but false: so the question is whether it makes a subjective claim and is right, or rather makes no subjective claim at all. How would you answer this as an external observer?

In the case of distinction, the fact that someone claims that one thing is distinct from another is caused by reality, whether the claim is true or false. So whether it is true or false depends on the way that it is caused by reality. In a similar way, the thing which apparently and objectively claims to possess subjective experience, is caused to do so by objective facts. Again, as in the case of distinction, whether it is true or false will depend on the way that it is caused to do so by objective facts.

We can give some obvious examples:

“This thing claims to possess subjective experience because it is a human being and does what humans normally do.” In this case, the objective and subjective claim is true, and is caused in the right way by objective facts.

“This thing claims to possess subjective experience because it is a very simple computer given a very simple program to output ‘I have subjective experience’ on its screen.” In this case the external claim is false, and it is caused in the wrong way by objective facts, and there is no subjective claim at all.

But how do you know for sure, someone will object. Perhaps the computer really is conscious, and perhaps the apparent human is a zombie. But we could similarly ask how we can know for sure that the person who came yesterday isn’t the same person who came today, even though they appear distant from each other, because perhaps the person is bilocating?

It would be mostly wrong to describe this situation by saying “there really is no hard problem of consciousness,” as Robin Hanson appears to do when he says, “People who think they can conceive of such zombies see a ‘hard question’ regarding which physical systems that claim to feel and otherwise act as if they feel actually do feel.” The implication seems to be that there is no hard question at all. But there is, and the fact that people engage in this discussion proves the existence of the question. Rather, we should say that the question is answerable, and that one it has been answered the remaining questions are “hard” only in the sense that it is hard to understand the world in general. The question is hard in exactly the way the question of Parmenides is hard: “How is it possible for one thing not to be another, when there is only being?” The question of consciousness is similar: “How is it possible for something to have subjective experience, when there are only objective things?” And the question can and should be answered in a similar fashion.

It would be virtually impossible to address every related issue in a simple blog post of this form, so I will simply mention some things that I have mainly set aside here:

1) The issue of formal causes, discussed more in my earlier treatment of this issue. This is relevant because “is this a zombie?” is in effect equivalent to asking whether the thing lacks a formal cause. This is worthy of a great deal of consideration and would go far beyond either this post or the earlier one.

2) The issue of “physical” and “material.” As I stated in this post, this is mainly a distraction. Most of the time, the real question is how the subjective is possible given that we believe that the world is objective. The only relevance of “matter” here is that it is obvious that a material thing is an objective thing. But of course, an immaterial thing would also have to be objective in order to be a thing at all. Aristotle and many philosophers of his school make the specific argument that the human mind does not have an organ, but such arguments are highly questionable, and in my view fundamentally flawed. My earlier posts suffice to call such a conclusion into question, but do not attempt to disprove it, and the the topic would be worthy of additional consideration.

3) Specific questions about “what, exactly, would actually be conscious?” Now neglecting such questions might seem to be a cop-out, since isn’t this what the whole problem was supposed to be in the first place? But in a sense we did answer it. Take an apparent claim of something to be conscious. The question would be this: “Given how it was caused by objective facts to make that claim, would it be a reasonable claim for a subjective claimer to make?” In other words, we cannot assume in advance that it is subjectively making a claim, but if it would be a reasonable claim, it will (in general) be a true one, and therefore also a subjective one, for the same reason that we (in general) make true claims when we reasonably claim that one thing is not another. We have not answered this question only in the same sense that we have not exhaustively explained which things are distinct from which other things, and how one would know. But the question, e.g., “when if ever would you consider an artificial intelligence to be conscious?” is in itself also worthy of direct discussion.

4) The issue of vagueness. This issue in particular will cause some people to object to my answer here. Thus Alexander Pruss brings this up in a discussion of whether a computer could be conscious:

Now, intelligence could plausibly be a vague property. But it is not plausible that consciousness is a vague property. So, there must be some precise transition point in reliability needed for computation to yield consciousness, so that a slight decrease in reliability—even when the actual functioning is unchanged (remember that the Ci are all functioning in the same way)—will remove consciousness.

I responded in the comments there:

The transition between being conscious and not being conscious that happens when you fall asleep seems pretty vague. I don’t see why you find it implausible that “being conscious” could be vague in much the same way “being red” or “being intelligent” might be vague. In fact the evidence from experience (falling asleep etc) seems to directly suggest that it is vague.

Pruss responds:

When I fall asleep, I may become conscious of less and less. But I can’t get myself to deny that either it is definitely true at any given time that I am at least a little conscious or it is definitely true that I am not at all conscious.

But we cannot trust Pruss’s intuitions about what can be vague or otherwise. Pruss claims in an earlier post that there is necessarily a sharp transition between someone’s not being old and someone’s being old. I discussed that post here. This is so obviously false that it gives us a reason in general not to trust Alexander Pruss on the issue of sharp transitions and vagueness. The source of this particular intuition may be the fact that you cannot subjectively make a claim, even vaguely, without some subjective experience, as well as his general impression that vagueness violates the principles of excluded middle and non-contradiction. But in a similar way, you cannot be vaguely old without being somewhat old. This does not mean that there is a sharp transition from not being old to being old, and likewise it does not necessarily mean that there is a sharp transition from not having subjective experience to having it.

While I have discussed the issue of vagueness elsewhere on this blog, this will probably continue to be a reoccurring feature, if only because of those who cannot accept this feature of reality and insist, in effect, on “this or nothing.”

Zeal for Form, But Not According to Knowledge

Some time ago I discussed the question of whether the behavior of a whole should be predictable from the behavior of the parts, without fully resolving it. I promised at the time to revisit the question later, and this is the purpose of the present post.

In the discussion of Robin Hanson’s book Age of Em, we looked briefly at his account of the human mind. Let us look at a more extended portion of his argument about the mind:

There is nothing that we know of that isn’t described well by physics, and everything that physicists know of is well described as many simple parts interacting simply. Parts are localized in space, have interactions localized in time, and interactions effects don’t move in space faster than the speed of light. Simple parts have internal states that can be specified with just a few bits (or qubits), and each part only interacts directly with a few other parts close in space and time. Since each interaction is only between a few bits on a few sides, it must also be simple. Furthermore, all known interactions are mutual in the sense that the state on all sides is influenced by states of the other sides.

For example, ordinary field theories have a limited number of fields at each point in space-time, with each field having a limited number of degrees of freedom. Each field has a few simple interactions with other fields, and with its own space-time derivatives. With limited energy, this latter effect limits how fast a field changes in space and time.

As a second example, ordinary digital electronics is made mostly of simple logic units, each with only a few inputs, a few outputs, and a few bits of internal state. Typically: two inputs, one output, and zero or one bits of state. Interactions between logic units are via simple wires that force the voltage and current to be almost the same at matching ends.

As a third example, cellular automatons are often taken as a clear simple metaphor for typical physical systems. Each such automation has a discrete array of cells, each of which has a few possible states. At discrete time steps, the state of each cell is a simple standard function of the states of that cell and its neighbors at the last time step. The famous “game of life” uses a two dimensional array with one bit per cell.

This basic physics fact, that everything is made of simple parts interacting simply, implies that anything complex, able to represent many different possibilities, is made of many parts. And anything able to manage complex interaction relations is spread across time, constructed via many simple interactions built up over time. So if you look at a disk of a complex movie, you’ll find lots of tiny structures encoding bits. If you look at an organism that survives in a complex environment, you’ll find lots of tiny parts with many non-regular interactions.

Physicists have learned that we only we ever get empirical evidence about the state of things via their interactions with other things. When such interactions the state of one thing create correlations with the state of another, we can use that correlation, together with knowledge of one state, as evidence about the other state. If a feature or state doesn’t influence any interactions with familiar things, we could drop it from our model of the world and get all the same predictions. (Though we might include it anyway for simplicity, so that similar parts have similar features and states.)

Not only do we know that in general everything is made of simple parts interacting simply, for pretty much everything that happens here on Earth we know those parts and interactions in great precise detail. Yes there are still some areas of physics we don’t fully understand, but we also know that those uncertainties have almost nothing to say about ordinary events here on Earth. For humans and their immediate environments on Earth, we know exactly what are all the parts, what states they hold, and all of their simple interactions. Thermodynamics assures us that there can’t be a lot of hidden states around holding many bits that interact with familiar states.

Now it is true that when many simple parts are combined into complex arrangements, it can be very hard to calculate the detailed outcomes they produce. This isn’t because such outcomes aren’t implied by the math, but because it can be hard to calculate what math implies. When we can figure out quantities that are easier to calculate, as long as the parts and interactions we think are going on are in fact the only things going on, then we usually see those quantities just as calculated.

The point of Robin’s argument is to take a particular position in regard to the question we are revisiting in this post: everything that is done by wholes is predictable from the behavior of the parts. The argument is simply a more extended form of a point I made in the earlier post, namely that there is no known case where the behavior of a whole is known not to be predictable in such a way, and many known cases where it is certainly predictable in this way.

The title of the present post of course refers us to this earlier post. In that post I discussed the tendency to set first and second causes in opposition, and noted that the resulting false dichotomy leads to two opposite mistakes, namely the denial of a first cause on one hand, and to the assertion that the first cause does or should work without secondary causes on the other.

In the same way, I say it is a false dichotomy to set the work of form in opposition with the work of matter and disposition. Rather, they produce the same thing, both according to being and according to activity, but in different respects. If this is the case, it will be necessarily true from the nature of things that the behavior of a whole is predictable from the behavior of the parts, but this will happen in a particular way.

I mentioned an example of the same false dichotomy in the post on Robin’s book. Here again is his argument:

But consider a key question: Does this other feeling stuff interact with the familiar parts of our world strongly and reliably enough to usually be the actual cause of humans making statements of feeling like this?

If yes, this is a remarkably strong interaction, making it quite surprising that physicists have missed it so far. So surprising in fact as to be frankly unbelievable. If this type of interaction were remotely as simple as all the interactions we know, then it should be quite measurable with existing equipment. Any interaction not so measurable would have be vastly more complex and context dependent than any we’ve ever seen or considered. Thus I’d bet heavily and confidently that no one will measure such an interaction.

But if no, if this interaction isn’t strong enough to explain human claims of feeling, then we have a remarkable coincidence to explain. Somehow this extra feeling stuff exists, and humans also have a tendency to say that it exists, but these happen for entirely independent reasons. The fact that feeling stuff exists isn’t causing people to claim it exists, nor vice versa. Instead humans have some sort of weird psychological quirk that causes them to make such statements, and they would make such claims even if feeling stuff didn’t exist. But if we have a good alternate explanation for why people tend to make such statements, what need do we have of the hypothesis that feeling stuff actually exists? Such a coincidence seems too remarkable to be believed.

I am currently awake and conscious, hearing the sounds of my keyboard as I type and the music playing in the background. Robin’s argument is something like this: why did I type the previous sentence? Is it because I am in fact awake and conscious and actually heard these sounds? If in principle it is predictable that I would have typed that, based on the simple interactions of simple parts, that seems to be an entirely different explanation. So either one might be the case or the other, but not both.

We have seen this kind of argument before. C.S. Lewis made this kind of argument when he said that thought must have reasons only, and no causes. Similarly, there is the objection to the existence of God, “But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist.” Just as in those cases we have a false dichotomy between the first cause and secondary causes, and between the final cause and efficient causes, so here we have a false dichotomy between form and matter.

Let us consider this in a simpler case. We earlier discussed the squareness of a square. Suppose someone attempted to apply Robin’s argument to squares. The equivalent argument would say this: all conclusions about squares can be proved from premises about the four lines that make it up and their relationships. So what use is this extra squareness? We might as well assume it does not exist, since it cannot explain anything.

In order to understand this one should consider why we need several kinds of cause in the first place. To assign a cause is just to give the origin of a thing in a way that explains it, while explanation has various aspects. In the linked post, we divided causes into two, namely intrinsic and extrinsic, and then divided each of these into two. But consider what would happen if we did not make the second division. In this case, there would be two causes of a thing: matter subject to form, and agent intending an end. We can see from this how the false dichotomies arise: all the causality of the end must be included in some way in the agent, since the end causes by informing the agent, and all the causality of the form must be included in some way in the matter, since the form causes by informing the matter.

In the case of the square, even the linked post noted that there was an aspect of the square that could not be derived from its properties: namely, the fact that a square is one figure, rather than simply many lines. This is the precise effect of form in general: to make a thing be what it is.

Consider Alexander Pruss’s position on artifacts. He basically asserted that artifacts do not truly exist, on the grounds that they seem to be lacking a formal cause. In this way, he says, they are just a collection of parts, just as someone might suppose that a square is just a collection of lines, and that there is no such thing as squareness. My response there was the same as my response about the square: saying that this is just a collection cannot explain why a square is one figure, nor can the same account explain the fact that artifacts do have a unity of some kind. Just as the denial of squareness would mean the denial of the existence of a unified figure, so the denial of chairness would mean the denial of the existence of chairs. Unlike Sean Carroll, Pruss seems even to recognize that this denial follows from his position, even if he is ambivalent about it at times.

Hanson’s argument about the human mind is actually rather similar to Pruss’s argument about artifacts, and to Carroll’s argument about everything. The question of whether or not the fact that I am actually conscious influences whether I say that I am, is a reference to the idea of a philosophical zombie. Robin discusses this idea more directly in another post:

Carroll inspires me to try to make one point I think worth making, even if it is also ignored. My target is people who think philosophical zombies make sense. Zombies are supposedly just like real people in having the same physical brains, which arose the through the same causal history. The only difference is that while real people really “feel”, zombies do not. But since this state of “feeling” is presumed to have zero causal influence on behavior, zombies act exactly like real people, including being passionate and articulate about claiming they are not zombies. People who think they can conceive of such zombies see a “hard question” regarding which physical systems that claim to feel and otherwise act as if they feel actually do feel. (And which other systems feel as well.)

The one point I want to make is: if zombies are conceivable, then none of us will ever have any more relevant info than we do now about which systems actually feel. Which is pretty much zero info! You will never have any info about whether you ever really felt in the past, or will ever feel in the future. No one part of your brain ever gets any info from any other part of your brain about whether it really feels.

These claims all follow from our very standard and well-established info theory. We get info about things by interacting with them, so that our states become correlated with the states of those things. But by assumption this hypothesized extra “feeling” state never interacts with anything. The actual reason why you feel compelled to assert very confidently that you really do feel has no causal connection with whether you actually do really feel. You would have been just as likely to say it if it were not true. What could possibly be the point of hypothesizing and forming beliefs about states about which one can never get any info?

We noted the unresolved tension in Sean Carroll’s position. The eliminativists are metaphysically correct, he says, but they are mistaken to draw the conclusion that the things of our common experience do not exist. The problem is that given that he accepts the eliminativist metaphysics, he can have no justification for rejecting their conclusions. We can see the same tension in Robin Hanson’s account of consciousness and philosophical zombies. For example, why does he say that they do not “make sense,” rather than asking whether or not they can exist and why or why not?

Let us think about this in more detail. And to see more clearly the issues involved, let us consider a simpler case. Take the four chairs in Pruss’s office. Is it possible that one of them is a zombie?

What would this even mean? In the post on the relationship of form and reality, we noted that asking whether something has a form is very close to the question of whether something is real. I really have two hands, Pruss says, if my hands have forms. And likewise chairs are real chairs if they have the form of a chair, and if they do not, they are not real in the first place, as Pruss argues is the case.

The zombie question about the chair would then be this: is it possible that one of the apparent chairs, physically identical to a real chair, is yet not a real chair, while the three others are real?

We should be able to understand why someone would want to say that the question “does not make sense” here. What would it even be like for one of the chairs not to be a real chair, especially if it is posited to be identical to all of the others? In reality, though, the question does make sense, even if we answer that the thing cannot happen. In this case it might actually be more possible than in other cases, since artifacts are in part informed by human intentions. But possible or not, the question surely makes sense.

Let us consider the case of natural things. Consider the zombie oak tree: it is physically identical to an oak tree, but it is not truly alive. It appears to grow, but this is just the motion of particles. There are three positions someone could hold: no oak trees are zombie oaks, since all are truly alive and grow; all oak trees are zombies, since all are mere collections of particles; and some are alive and grow, while others are zombies, being mere collections of particles.

Note that the question does indeed make sense. It is hard to see why anyone would accept the third position, but if the first and second positions make sense, then the third does as well. It has an intelligible content, even if it is one that we have no good arguments for accepting. The argument that it does not make sense is basically the claim that the first and second positions are not distinct positions: they do not say different things, but the same thing. Thus the the third would “not make sense” insofar as it assumes that the first and second positions are distinct positions.

Why would someone suppose that the first and second positions are not distinct? This is basically Sean Carroll’s position, since he tries to say both that eliminativists are correct about what exists, but incorrect in denying the existence of common sense things like oak trees. It is useful to say, “oak trees are real,” he says, and therefore we will say it, but we do not mean to say something different about reality than the eliminativists who say that “oak trees are not real but mere collections of particles.”

But this is wrong. Carroll’s position is inconsistent in virtually the most direct possible way. Either oak trees are real or they are not; and if they are real, then they are not mere collections of particles. So both the first and second positions are meaningful, and consequently also the third.

The second and third positions are false, however, and the meaningfulness of this becomes especially clear when we speak of the human case. It obviously does make sense to ask whether other human beings are conscious, and this is simply to ask whether their apparent living activities, such as speaking and thinking, are real living activities, or merely apparent ones: perhaps the thing is making sounds, but it is not truly speaking or thinking.

Let us go back to the oak tree for a moment. The zombie oak would be one that is not truly living, but its activities, apparently full of life, are actually lifeless. In order to avoid this possibility, and out of a zeal for form which is not according to knowledge, some assert that the activities of an oak cannot be understood in terms of the activities of the parts. There is a hint of this, perhaps, in this remark by James Chastek:

Consciousness is just the latest field where we are protesting that something constitutes a specific difference from some larger genus, but if it goes the way the others have gone, in fifty years no one will even remember the controversy or bother to give the fig-leaf explanations of it being emergent or reductive. No one will remember that there is a difference to explain. Did anyone notice in tenth-grade biology that life was explained entirely in terms of non-living processes? No. There was nothing to explain since nothing was noticed.

Chastek does not assert that life cannot be “explained entirely in terms of non-living processes,” in the manner of tenth-grade biology, but he perhaps would prefer that it could not be so explained. And the reason for this would be the idea that if everything the living thing does can be explained in terms of the parts, then oak trees are zombies after all.

But this idea is mistaken. Look again at the square: the parts explain everything, except the fact that the figure is one figure, and a square. The form of a square is indeed needed, precisely in order that the thing will actually be a whole and a square.

Likewise with the oak. If an oak tree is made out of parts, then since activity follows being, it should be unsurprising that in some sense its activities themselves will be made out of parts, namely the activities of its parts. But the oak is real, and its activities are real. And just as oaks really exist, so they really live and grow; but just as the living oak has parts which are not alive in themselves, such as elements, so the activity of growth contains partial activities which are not living activities in themselves. What use is the form of an oak, then? It makes the tree really an oak and really alive; and it makes its activities living activities such as growth, rather than being merely a collection of non-living activities.

We can look at human beings in the same way, but I will leave the details of this for another post, since this one is long enough already.

Form and Reality

In a very interesting post Alexander Pruss discusses realism and skeptical scenarios:

The ordinary sentence “There are four chairs in my office” is true (in its ordinary context). Furthermore, its being true tells us very little about fundamental ontology. Fundamental physical reality could be made out of a single field, a handful of fields, particles in three-dimensional space, particles in ten-dimensional space, a single vector in a Hilbert space, etc., and yet the sentence could be true.

An interesting consequence: Even if in fact physical reality is made out of particles in three-dimensional space, we should not analyze the sentence to mean that there are four disjoint pluralities of particles each arranged chairwise in my office. For if that were what the sentence meant, it would tell us about which of the fundamental physical ontologies is correct. Rather, the sentence is true because of a certain arrangement of particles (or fields or whatever).

If there is such a broad range of fundamental ontologies that “There are four chairs in my office” is compatible with, it seems that the sentence should also be compatible with various sceptical scenarios, such as that I am a brain in a vat being fed data from a computer simulation. In that case, the chair sentence would be true due to facts about the computer simulation, in much the way that “There are four chairs in this Minecraft house” is true. It would be very difficult to be open to a wide variety of fundamental physics stories about the chair sentence without being open to the sentence being true in virtue of facts about a computer simulation.

But now suppose that the same kind of thing is true for other sentences about physical things like tables, dogs, trees, human bodies, etc.: each of these sentences can be made true by a wide array of physical ontologies. Then it seems that nothing we say about physical things rules out sceptical scenarios: yes, I know I have two hands, but my having two hands could be grounded by facts about a computer simulation. At this point the meaningfulness of the sceptical question whether I know I am not a brain in a vat is breaking down. And with it, realism is breaking down.

I am not completely sure what Pruss means by “realism is breaking down,” but he is looking at something important here. One question that needs to be addressed, however, is what counts as a skeptical scenario in the first place. In the rest of the post, Pruss makes an interesting suggestion about this:

In order for the sceptical question to make sense, we need the possibility of saying things that cannot simply be made true by a very wide variety of physical theories, since such things will also be made true by computer simulations. This gives us an interesting anti-reductionist argument. If the statement “I have two hands” is to be understood reductively (and I include non-Aristotelian functionalist views as reductive), then it could still be literally true in the brain-in-a-vat scenario. But if anti-reductionism about hands is true, then the statement wouldn’t be true in the brain-in-a-vat scenario. And so I can deny that I am in that scenario simply by saying “I have two hands.”

But maybe I am moving too fast here. Maybe “I have two hands” could be literally true in a brain-in-a-vat scenario. Suppose that the anti-reductionism consists of there being Aristotelian forms of hands (presumably accidental forms). But if, for all we know, the form of a hand can inform a bunch of particles, a fact about a vector or the region of a field, then the form of a hand can also inform an aspect of a computer simulation. And so, for all we know, I can literally and non-reductively have hands even if I am a brain in a vat. I am not sure, however, that I need to worry about this. What is important is form, not the precise material substrate. If physical reality is the memory of a giant computer but it isn’t a mere simulation but is in fact informed by a multiplicity of substantial and accidental forms corresponding to people, trees, hands, hearts, etc., and these forms are real entities, then the scenario does not seem to me to be a sceptical scenario.

A skeptical scenario, according to Pruss, is a situation where the things we normally talk about do not have forms. If they do have forms, we are not in a skeptical scenario at all, even if in some sense we are in a computer simulation or even if someone is a brain in a vat. On the face of it this seems a very odd claim: “form” seems to be a technical philosophical explanation, while asking if we are in a skeptical scenario seems to be asking if our everyday common sense understanding of things is mistaken.

Nonetheless, there is a lot of truth in his explanation. First let us consider what is meant by a skeptical scenario in the first place. In terms of his example, it is supposed to go something like this: “Is it possible that you are a brain in a vat without realizing it? If so, then almost everything you believe is false, since you do not have hands, the people you speak to are not real, and so on.”

In the post Pruss is pointing out a problem with the skeptical question. The skeptical question is like a skeptic in the remote past asking, “Is it possible that the earth is spinning without us realizing it? If so, then our everyday opinion that the sun rises every morning is false, since the sun does not move.”

The response to the second skeptic is evident: our everyday opinion that the sun rises every morning is not false, not even if the earth turns out to be spinning, because “the sun rises every morning,” is to be understood in whatever way is needed in order for it to be true. It refers to what happens every morning, whatever that actually happens to be.

Pruss is pointing out that we can answer the first question in the same way: our everyday opinion that we have hands is not false, not even if we are in a computer simulation or in a vat, because “I have two hands” is to be understood in whatever way is needed in order for it to be true. It refers to these two things in front of me right now, whatever they actually are.

Let’s suppose the skeptic tries to come up with a response. He might say, “Look, computer programs do not have hands, and brains do not have hands. So if you are a computer program or a brain in a vat, then you just do not have hands, period. So those scenarios do indeed mean that your common understanding would be false.”

It is certainly true that according to our common understanding, brains in vats do not have hands. So there is a tension here: the argument that it would be true to say we have hands even in that situation seems like a good argument, but so does the argument that it would be false that we have hands.

The answer to the difficulty is that we need to consider the meaning of “I am a brain in a vat.” Just as the word “hands” should refer to these two things in front of me, whatever they are, so the word “brain” refers to things inside of people’s heads, whatever they are, and the word “vat” refers to other things we sometimes experience in real life, at occasionally, or something very like them. But this means that just as “I have two hands” is to be understood in whatever way is needed to make it true, so also “I am not a brain in a vat,” is understood in whatever way is needed to make it true.

This means that correct answer to the original question was simply, “No, it isn’t possible that I will turn out to be a brain in a vat, regardless of any later discoveries, and it isn’t possible that the sun will turn out not to rise, regardless of discoveries about the motion of the sun and of the earth.”

The skeptic will want to insist. Surely events like those of The Matrix are at least conceivable. And if some such situation turned out to be true, then wasn’t it true that you were in a skeptical scenario and that your beliefs about hands and brains and vats were all false, and especially would it not be the case that your belief that you weren’t in a situation like that was false?

The correct answer, again, is that your original beliefs were not false. But in view of your new knowledge of the world, you might well want to adopt a new mode of speaking, and say things that would sound opposed to your original beliefs. They would not be opposed, however, but would simply be speaking about things you did not originally speak about.

Note however that “your belief that you weren’t in a situation like that” could now be taken in two ways. It could mean my belief that I am not a brain in a vat, and this belief will never turn out to have been false. Or it could mean a belief that there is not some larger view of reality where “he was a brain in a vat” would be a reasonable description, in the way that someone coming out of the Matrix would acquire a larger view. In reality I have the latter belief as well, as I consider it improbable that any intelligent beings would behave in such a way as to make that scenario probable. But I don’t think it is impossible for this belief to be falsified; and if it were, I would not say that my previous common sense beliefs had been false. This corresponds to what Pruss says at the end of his post, where he says that as long as things have forms, it is not really a skeptical scenario, even if in some sense he is in a computer simulation or whatever.

Why the insistence on form? This is related to what we called the Semi-Parmenidean Heresy. There we discussed Sean Carroll’s view, and noted that his position in essence is this: Metaphysically, the eliminativists are right. But it is useful to talk as though they are wrong, so we’re going to talk as though they are wrong, and even say they are wrong, by saying that common sense things are real.

This is ultimately incoherent: if the eliminativists are mistaken, they are mistaken in their metaphysics, since the position is just a certain metaphysical position.

It is not difficult to see the connection. According to a strict eliminativist, it would be literally true that we do not have hands, because there is no such thing as “we” or as “hands” in the first place. There are just fundamental particles. In other words, eliminativism would be even more of a skeptical scenario than the Matrix; the Matrix would not imply that your common sense beliefs are false, while eliminativism simply says that all of your beliefs are false, including your belief that you have beliefs.

And on the other hand, no scenario will be truly skeptical, even one like the Matrix, if it admits that our common sense beliefs are true. And as I said at the end of the post on Carroll’s view, this requires a metaphysics that allows those beliefs to be true, and this requires formal causes.

Alexander Pruss, however, seems to me to interpret this in a rather narrow way in his concluding remark:

If physical reality is the memory of a giant computer but it isn’t a mere simulation but is in fact informed by a multiplicity of substantial and accidental forms corresponding to people, trees, hands, hearts, etc., and these forms are real entities, then the scenario does not seem to me to be a sceptical scenario.

It is not clear what it means to be “real entities” rather than being unreal, given that you acknowledge them in the first place, and it isn’t clear to me what he means by a “mere simulation.” But this sounds a lot to me like, “If the world isn’t Aristotelian, understood in a very narrow way, then that would be a skeptical scenario.” This seems to me a kind of stubbornness much like that of James Larson. Disagreeing with you is not a war against being, and believing that your account of form and matter didn’t get every detail right, is not saying that our common sense beliefs are not true.

As an illustration of the narrowness in question, consider Pruss’s position on artifacts:

Suppose I am a plumber, and I take a section of pipe, insert a blowgun dart, and blow.  I just shot a dart out of a blowgun.  When did the pipe turn into a blowgun, though?

Did it happen when I formed the intention to use the pipe as a blowgun?  No: I do not have the power to make new material objects come into existence just by thinking about it.

When I picked up the pipe?  There are at least there is contact.  But surely it’s not the right kind of contact.  It would be magic if I could make a new material object come into existence by just picking up a material object with a certain thought in mind.

When I inserted the dart?  Presumably, not any insertion will do, but one with a plan to blow.  For I could just be doing plumbing, using the outer diameter of the dart to measure the inner diameter of the pipe, and that shouldn’t turn the pipe into a dart.  Again, we have some magic here–thinking about the pipe in one way while inserting the dart creates a blowgun while thinking about it another way leaves it a boring pipe.  Moreover, putting the dart into the pipe seems to be an instance of loading a blowgun rather than making a blowgun.

The solution to all this is to deny that there are pipes and blowguns.  There is just matter (or fields) arranged pipewise and blowgunwise.  And for convenience we adopt ways of speaking that make it sound like such objects are among the furniture of the universe.

Pruss is not simply putting out a position for discussion; this is what he believes to be true, as is easily confirmed elsewhere on his blog. Note that he is falling into the Semi-Parmenidean heresy here, except that he is even going farther than Carroll, and suggesting that “there are no pipes and blowguns” is a true statement, which Carroll would rightly deny. In this way Pruss is almost a pure eliminativist about artifacts. (He does also speak elsewhere more in the manner of Sean Carroll about them.)

To the degree that he is eliminativist about artifacts, he contradicts common sense in the same kind of way that someone contradicts common sense who says, “You do not have hands.” He just contradicts it about different things. And why about these things, and not others? I suggest that it is because under the ordinary Aristotelian account, it is likely that a man or a horse has a substantial form, but unlikely that a pipe has one. And although a pipe would have various accidental forms, the idea of a unified form of “pipeness” seems pretty unlikely. If this is actually his reason or part of it, then he is identifying skepticism with disagreeing with his philosophical opinions, even though his own opinions actually contain the skepticism: namely, disagreement with common sense.

My own response to this question would be different: being is said in many ways, and consequently also form and unity. And I reject any disagreement with common sense: men and horses are real, but so also are pipes. If I am not mistaken, all of these will have being and form in the way that is appropriate to them.

Semi-Parmenidean Heresy

In his book The Big Picture, Sean Carroll describes the view which he calls “poetic naturalism”:

As knowledge generally, and science in particular, have progressed over the centuries, our corresponding ontologies have evolved from quite rich to relatively sparse. To the ancients, it was reasonable to believe that there were all kinds of fundamentally different things in the world; in modern thought, we try to do more with less.

We would now say that Theseus’s ship is made of atoms, all of which are made of protons, neutrons, and electrons-exactly the same kinds of particles that make up every other ship, or for that matter make up you and me. There isn’t some primordial “shipness” of which Theseus’s is one particular example; there are simply arrangements of atoms, gradually changing over time.

That doesn’t mean we can’t talk about ships just because we understand that they are collections of atoms. It would be horrendously inconvenient if, anytime someone asked us a question about something happening in the world, we limited our allowable responses to a listing of a huge set of atoms and how they were arranged. If you listed about one atom per second, it would take more than a trillion times the current age of the universe to describe a ship like Theseus’s. Not really practical.

It just means that the notion of a ship is a derived category in our ontology, not a fundamental one. It is a useful way of talking about certain subsets of the basic stuff of the universe. We invent the concept of a ship because it is useful to us, not because it’s already there at the deepest level of reality. Is it the same ship after we’ve gradually replaced every plank? I don’t know. It’s up to us to decide. The very notion of “ship” is something we created for our own convenience.

That’s okay. The deepest level of reality is very important; but all the different ways we have of talking about that level are important too.

There is something essentially pre-Socratic about this thinking. When Carroll talks about “fundamentally different things,” he means things that differ according to their basic elements. But at the same kind the implication is that only things that differ in this way are “fundamentally” different in the sense of being truly or really different. But this is a quite different sense of “fundamental.”

I suggested in the linked post that even Thales might not really have believed that material causes alone sufficiently explained reality. Nonetheless, there was a focus on the material cause as being the truest explanation. We see the same focus here in Sean Carroll. When he says, “There isn’t some primordial shipness,” he is thinking of shipness as something that would have to be a material cause, if it existed.

Carroll proceeds to contrast his position with eliminativism:

One benefit of a rich ontology is that it’s easy to say what is “real”- every category describes something real. In a sparse ontology, that’s not so clear. Should we count only the underlying stuff of the world as real, and all the different ways we have of dividing it up and talking about it as merely illusions? That’s the most hard-core attitude we could take to reality, sometimes called eliminativism, since its adherents like nothing better than to go around eliminating this or that concept from our list of what is real. For an eliminativist, the question “Which Captian Kirk is the real one?” gets answered by, “Who cares? People are illusions. They’re just fictitious stories we tell about the one true world.”

I’m going to argue for a different view: our fundamental ontology, the best way we have of talking about the world at the deepest level, is extremely sparse. But many concepts that are part of non-fundamental ways we have of talking about the world- useful ideas describing higher-level, macroscopic reality- deserve to be called “real.”

The key word there is “useful.” There are certainly non-useful ways of talking about the world. In scientific contexts, we refer to such non-useful ways as “wrong” or “false.” A way of talking isn’t just a list of concepts; it will generally include a set of rules for using them, and relationships among them. Every scientific theory is a way of talking about the world, according to which we can say things like “There are things called planets, and something called the sun, all of which move through something called space, and planets do something called orbiting the sun, and those orbits describe a particular shape in space called an ellipse.” That’s basically Johannes Kepler’s theory of planetary motion, developed after Copernicus argued for the sun being at the center of the solar system but before Isaac Newton explained it all in terms of the force of gravity. Today, we would say that Kepler’s theory is fairly useful in certain circumstances, but it’s not as useful as Newton’s, which in turn isn’t as broadly useful as Einstein’s general theory of relativity.

A poetic naturalist will agree that both Captain Kirk and the Ship of Theseus are simply ways of talking about certain collections of atoms stretching through space and time. The difference is that an eliminativist will say “and therefore they are just illusions,” while the poetic naturalist says “but they are no less real for all of that.”

There are some good things about what Carroll is doing here. He is right of course to insist that the things of common experience are “real.” He is also right to see some relationship between saying that something is real and saying that talking about it is useful, but this is certainly worth additional consideration, and he does not really do it justice.

The problematic part is that, on account of his pre-Socratic tendencies, he is falling somewhat into the error of Parmenides. The error of Parmenides was to suppose that being can be, and can be thought and said, in only one way. Carroll, on account of confusing the various meanings of “fundamental,” supposes that being can be in only one way, namely as something elemental, but that it can be thought and said in many ways.

The problem with this, apart from the falsity of asserting that being can be in only one way, is that no metaphysical account is given whereby it would be reasonable to say that being can be thought and said in many ways, given that it can be in only one way. Carroll is trying to point in that direction by saying that our common speech is useful, so it must be about real things; but the eliminativist would respond, “Useful to whom? The things that you are saying this is useful for are illusions and do not exist. So even your supposed usefulness does not exist.” And Carroll will have no valid response, because he has already admitted to agreeing with the eliminativist on a metaphysical level.

The correct answer to this is the one given by Aristotle. Material causes do not sufficiently explain reality, but other causes are necessary as well. But this means that the eliminativist is mistaken on a metaphysical level, not merely in his way of speaking.

Parmenides the Eliminativist

While the name “eliminativism” is used particularly with respect to the denial of the reality of consciousness or various mental conditions, we could define it more generally as the tendency to explain something away rather than explaining it. The motive for this would be that someone believes that reality does not have the principles needed in order to explain the thing; so it is necessary for them to explain it away instead. In this way we noted that Daniel Dennett denies the existence of consciousness. Since every being is objective, in his view, reality does not have any principle which could explain something subjective. Therefore it is necessary for him to explain away subjectivity.

If we take eliminativism in this general way, it will turn out that Parmenides is the ultimate eliminativist. According to Parmenides, not only is there nothing but being, but nothing can be distinct from being in any way, even in concept. Thus anything which appears to be conceptually distinct from being, including ourselves and all the objects of our common experience, is nothing but an illusion deluding itself. And ultimately nothing at all, since even illusions cannot be something other than being.

Parmenides comes to this conclusion in the same general way as Dennett, namely because it seems to him that reality cannot have any principle which could explain things as they are. It is evident that there cannot be anything besides being; thus if something seems distinct from being in any way, there is no principle capable of explaining it.

Descartes argued that he can know he exists since he thinks. On the contrary , Parmenides responds: you think, but thinking means something different from being; therefore you are not.